The present disclosure relates to recovery of hydrocarbons, and more particularly, to the recovery of hydrocarbons using a recovery fluid.
The hydrocarbons residing in some geological formations are of a high viscosity. These high viscosity hydrocarbons are referred to generally as heavy oil, and can include high viscosity oil, tar, bitumen, and asphalt. Because of their high viscosity, these hydrocarbons are not mobile within the formation, and are thus difficult to recover. In the past, the high viscosity hydrocarbons remained untapped due to an inability to economically recover them. More recently, as the demand for oil has increased, commercial operations have expanded to the recovery of such heavy oil deposits. In some circumstances, the application of heated fluids (e.g., steam) or solvents to the formation are used to reduce the viscosity of the hydrocarbons. Reducing the viscosity of the hydrocarbons mobilizes them within the formation and permits their extraction to the surface. The methods by which heavy oils are recovered, however, are still evolving. Improvements in the operational efficiencies of these methods decrease the cost of recovering heavy oils and may make additional deposits economically viable.